From: Xiyu Yang xiyuyang19@fudan.edu.cn
[ Upstream commit e3436ce60cf5f5eaedda2b8c622f69feb97595e2 ]
gasket_sysfs_register_store() invokes get_mapping(), which returns a reference of the specified gasket_sysfs_mapping object to "mapping" with increased refcnt.
When gasket_sysfs_register_store() returns, local variable "mapping" becomes invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of gasket_sysfs_register_store(). When gasket_dev is NULL, the function forgets to decrease the refcnt increased by get_mapping(), causing a refcnt leak.
Fix this issue by calling put_mapping() when gasket_dev is NULL.
Signed-off-by: Xiyu Yang xiyuyang19@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com Link: https://lore.kernel.org/r/1587618941-13718-1-git-send-email-xiyuyang19@fudan... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/staging/gasket/gasket_sysfs.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/staging/gasket/gasket_sysfs.c b/drivers/staging/gasket/gasket_sysfs.c index 9c982f1c0881..5986c67bc7ec 100644 --- a/drivers/staging/gasket/gasket_sysfs.c +++ b/drivers/staging/gasket/gasket_sysfs.c @@ -377,6 +377,7 @@ ssize_t gasket_sysfs_register_store(struct device *device, gasket_dev = mapping->gasket_dev; if (!gasket_dev) { dev_err(device, "Device driver may have been removed\n"); + put_mapping(mapping); return 0; }